2,167 research outputs found
Acoustic charge transport in n-i-n three terminal device
We present an unconventional approach to realize acoustic charge transport
devices that takes advantage from an original input region geometry in place of
standard Ohmic input contacts. Our scheme is based on a n-i-n lateral junction
as electron injector, an etched intrinsic channel, a standard Ohmic output
contact and a pair of in-plane gates. We show that surface acoustic waves are
able to pick up electrons from a current flowing through the n-i-n junction and
steer them toward the output contact. Acoustic charge transport was studied as
a function of the injector current and bias, the SAW power and at various
temperatures. The possibility to modulate the acoustoelectric current by means
of lateral in-plane gates is also discussed. The main advantage of our approach
relies on the possibility to drive the n-i-n injector by means of both voltage
or current sources, thus allowing to sample and process voltage and current
signals as well.Comment: 9 pages, 3 figures. Submitted to Applied Physics Letter
Separating arbitrary free-space beams with an integrated photonic processor
: Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit's optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems
An Expert Consensus Framework for Asthma Remission as a Treatment Goal
With novel therapies in development, there is an opportunity to consider asthma remission as a treatment goal. In this Rostrum, we present a generalized framework for clinical and complete remission in asthma, on and off treatment, developed on the basis of medical literature and expert consensus. A modified Delphi survey approach was used to ascertain expert consensus on core components of asthma remission as a treatment target. Phase 1 identified other chronic inflammatory diseases with remission definitions. Phase 2 evaluated components of those definitions as well as published definitions of spontaneous asthma remission. Phase 3 evaluated a remission framework created using consensus findings. Clinical remission comprised 12 or more months with (1) absence of significant symptoms by validated instrument, (2) lung function optimization/stabilization, (3) patient/provider agreement regarding remission, and (4) no use of systemic corticosteroids. Complete remission was defined as clinical remission plus objective resolution of asthma-related inflammation and, if appropriate, negative bronchial hyperresponsiveness. Remission off treatment required no asthma treatment for 12 or more months. The proposed framework is a first step toward developing asthma remission as a treatment target and should be refined through future research, patient input, and clinical study
OCS Reduction According to the Presence of Nasal Polyps or Atopic Status in the PONENTE Study
Peer reviewedPostprin
Adrenal Insufficiency is Not a Barrier to OCS Elimination in the PONENTE Study
Peer reviewedPostprin
Heterogeneity within and between physician-diagnosed asthma and/or COPD : NOVELTY cohort
Copyright ©The authors 2021. For reproduction rights and permissions contact [email protected] reviewedPublisher PD
The Hot and Energetic Universe: The close environments of supermassive black holes
Most of the action in Active Galactic Nuclei (AGN) occurs within a few tens
of gravitational radii from the supermassive black hole, where matter in the
accretion disk may lose up to almost half of its energy with a copious
production of X-rays, emitted via Comptonization of the disk photons by hot
electrons in a corona and partly reflected by the accretion disk. Thanks to its
large effective area and excellent energy resolution, Athena+ contributions in
the understanding of the physics of accretion in AGN will be fundamental - and
unique - in many respects. It will allow us to map the disk-corona system -
which is crucial to understand the mechanism of energy extraction and the
relation of the corona with winds and jets - by studying the time lags between
reflected and primary photons. These lags have been recently discovered by
XMM-Newton, but only Athena+ will have the sensitivity required to fully
exploit this technique. Athena+ will also be able e.g. to determine robustly
the spin of the black hole in nearby sources (and to extend these measurements
beyond the local Universe), to establish the nature of the soft X-ray
components, and to map the circumnuclear matter within the AGN inner parsec
with unprecedented details.Comment: Supporting paper for the science theme "The Hot and Energetic
Universe" to be implemented by the Athena+ X-ray observatory
(http://www.the-athena-x-ray-observatory.eu). 9 pages, 8 figure
Seasonal changes in plankton respiration and bacterial metabolism in a temperate shelf sea
The seasonal variability of plankton metabolism indicates how much carbon is cycling within a system, as well as its capacity to store carbon or export organic matter and CO2 to the deep ocean. Seasonal variability between November 2014, April 2015 and July 2015 in plankton respiration and bacterial (Bacteria+Archaea) metabolism is reported for the upper and bottom mixing layers at two stations in the Celtic Sea, UK. Upper mixing layer (UML, >75 m in November, 41 - 70 m in April and ~50 m in July) depth-integrated plankton metabolism showed strong seasonal changes with a maximum in April for plankton respiration (1.2- to 2-fold greater compared to November and July, respectively) and in July for bacterial production (2-fold greater compared to November and April). However UML depth-integrated bacterial respiration was similar in November and April and 2-fold lower in July. The greater variability in bacterial production compared to bacterial respiration drove seasonal changes in bacterial growth efficiencies, which had maximum values of 89 % in July and minimum values of 5 % in November. Rates of respiration and gross primary production (14C-PP) also showed different seasonal patterns, resulting in seasonal changes in 14C-PP:CRO2 ratios. In April, the system was net autotrophic (14C-PP:CRO2 > 1), with a surplus of organic matter available for higher trophic levels and export, while in July balanced metabolism occurred (14C-PP:CRO2 = 1) due to an increase in plankton respiration and a decrease in gross primary production. Comparison of the UML and bottom mixing layer indicated that plankton respiration and bacterial production were higher (between 4 and 8-fold and 4 and 7-fold, respectively) in the UML than below. However, the rates of bacterial respiration were not statistically different (p > 0.05) between the two mixing layers in any of the three sampled seasons. These results highlight that, contrary to previous data from shelf seas, the production of CO2 by the plankton community in the UML, which is then available to degas to the atmosphere, is greater than the respiratory production of dissolved inorganic carbon in deeper waters, which may contribute to offshore export
Ultrasound imaging versus morphopathology in cardiovascular diseases. Coronary collateral circulation and atherosclerotic plaque
This review article is aimed at comparing the results of histopathological and clinical imaging studies to assess coronary collateral circulation in humans. The role of collaterals, as emerging from morphological studies in both normal and atherosclerotic coronary vessels, is described; in addition, present role and future perpectives of echocardiographic techniques in assessing collateral circulation are briefly summarized
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